Pressure type liquid fuel burning device



May 15, 1945. R. BAKER EI'AL PRESSURE TYPE LIQUID FUEL BURNING DEVICEOriginal Filed Feb. l9, 1942 3 Sheets-Sheet l mvavroks R0 8 a RT BA KERCORTL 1w 0 W. DAVIS MI 6 flTTOENEZ y 1945- R, BAKER ETAL ,886

PRESSURE TYPE LIQUID FUEL BURNING DEVICE IOriginal Filed Feb. 19, 1942 3Sheets-Sheet 2 INVENTORS. ROBERT BAKER BY CORTLAND W DAV/6 Maw May 15,1945. R. BAKER ETAL 2,375,886

PRESSURE TYPE LIQUID FUEL BURNING DEVICE Original Filed Feb. 19, 1942 3Sheets-Sheet 3 w l I lllil A neurons. ROBERT BA KE R 6 8y CORTLAND w.DAVIS ATTORNEY Patented May 15, 1945 PRESSURE TYPE LIQUID FUEL BURNINGDEVICE Robert Baker, Alexandria, and Cortland W.

Davis, Summitville, Ind., assignors to The Mantie Lamp Company ofAmerica, Chicago, 111., a corporation of Illinois Original applicationFebruary 19, 1942, Serial No. 431,568. Divided and this applicationDecemher 17, 1942, Serial No. 469,300

6 Claims.

This invention pertains to an improved construction of liquid fuelburning devices of the pressure type, by which the starting operationinvolving the requisite preheating of the generator of the device isaccomplished without the use of an auxiliary starting torch or flame, bywhich an improved generator construction is employed which constitutesthe sole passageway of the atomized or vaporized fuel to the mixing tubefor both the starting and the running conditions of the device, by whichan improved single control valve mechanism is employed to control boththe starting and running conditions, as well as other mechanicalfeatures greatly facilitating economical construction of the device andits efficient operation. The invention is particularly applicable todifierent forms of pressure lighting devices of the mantle type, such aslanterns and lamps of various types, as well as to different types ofliquid fuel burning devices of the pressure type, such as stoves,torches and heating devices generally.

In addition to the above, the invention includes devices for efficientlyburning different kinds of liquid fuel as desired, for example gasolineat one time and kerosene at another time, b the simple expedient ofchanging the amount of air supplied to the mixing tube or manifold,depending upon the kind of fuel to be burned. The devices provided bythe invention for efficiently realizing the starting condition and forreducing the starting condition to a short time interval, include amechanical structure in the reservoir of the device by which the airunder pressure in said reser voir is utilized during the startingcondition to break up and atomize the liquid fuel then delivered by thevalve mechanism to the generator tube, the atomization being soeffective that the resulting fuel mixture may be lighted at once andburn without excessive smoking, to sufficiently heat the generator tubevery rapidly, even when kerosene is used as the fuel, so that the valvemechanism may be turned to its running condition within a brief intervalafter starting the burning of the fuel.

This is a divisional application of our copending application, SerialNumber 43. .568, filed February 19, 1942.

The above stated advantages constitute the objects of the invention,which, as well as the mechanical structures involved and their mode ofoperation, will be best understood by reference to the accompanyingdrawings illustrating a preferred embodiment of the invention, asapplied to a lantern of the mantle type, in which:

Fig. 2 is a horizontal, sectional view through the structure shown inFig. 1, taken along theconditions;

Fig. l is a vertical, central view. partially in Fig. 5 is a vertical,central, sectional view to any enlarged scale, through the upper portionof the mixing tube or chamber, corresponding to Fig. 3, and showing alsoin vertical, central, sectional view the generator tube of the lantern;

Fig. 5a i a sectional view to an enlarged scale of a part of thestructure shown in Fig. 5 taken along the line 5a5a;

Fig. 6 is a vertical, central, sectional view through the parts shown inFig. 5, taken along the line 6-6 in the latter figure, and

Fig. 7 is a detail view to an enlarged scale of the devices employed tochange the lantern from a condition for use with relatively heavy liquidfuel, to a condition for use with a relatively light liquid fuel andvice Versa, this view being taken along the line 1-1 in Fig. 1.

Similar numerals refer to similar parts throughout the several views.

As shown in Fig. the lantern consists of a metal reservoir lfl havingcentrally extending upwardly from its top Wall, the valve mechanism H,which valve mechanism is surrounded by a sheet metal sleeve l2 tosupport the base plate 13 of the lantern in horizontal position, thebase plate being held in place by a screw or bolt M extending centrallythrough the base plate into the housing of the valve mechanism l. Thebase plate I3 is provided with an upwardly extending edge flange Eta toform a seat for the lower end of the lantern chimney 15. The base platel3 has rigidly secured thereto, thelower ends of two air tubes [6 and I!which open without obstruction through the base plate, excepting thatthe air tube I1 is provided at its lower end as more clearly shown inFig. '7, with a gate or shutter l8 pivotally connected to the undersideof the base plate l3 at l9, and preferably having a projecting lug |8aby means of which the gate or shutter may be swung to a position Closingthe lower end of the air tube 1 I or to an alternate position openingthe lower end of said air tube, the closed condition of the air tube 51being that employed when the lantern is to be operated with a relativelylight liquid fuel such as gasoline, and th open position being thatemployed when the lantern is to be used with relatively heavy liquidfuel, such as kerosene.

The upper ends of the air tubes l6 and H are curved to extendhorizontally towards each other,

and preferably so that their upper ends have a common horizontal axis,said upper ends beingsecured in this position to a metal block 28, forexample by brazing. A sheet metal yoke 2i. is apertured at its lowerends to receive the upper ends of the air tubes IB and H, the spacing ofthe sides of the yoke 2| being equal to the lateral extent of the block20, and the yoke 2i is. rig-idly secured in a position extending.upwardly abovethe block 20, by having its lower ends secured to theupper ends of the air tubes l6 and I1 and to the block 28, for exampleby brazing. The upper horizontal portion of yoke 2| is sufficientlyspaced from the upper end of the block to permit the ready entrance andremoval of the nozzle 22 into and from the block 20 for assembling anddismantling operations. The upper horizontal portion of the yoke 2| hasrigidly secured thereto an upwardly extending screw 23 which projectsthrough inner and outer annular hood members 24- and 25 to rigidlysupport the hood members and hold them in place relatively to themechanical. frame work oi the lantern by a nut26 threaded on the screw23 above the hood member 25. The hood members 24 and 25 are preferablyrigidly secured together, for example by brazing or welding, toconstitute: a unitary structure.

The. inner and lower hood member 24 is cylindrical andv perforated atits upper portion, to provide ready egress for the gases of combustion,below which it is conieally flared outwardly and downwardly, andprovided at 24a. with an annular seat to receive the upper end of thechimney 15, said member.- 2-4 being, continued below and outwardly fromthe. upper end of the chimney, to. constitute a weather shield 24!; for

- the chimney. The outer hood member 25; is general-ly spherical inshape and, extends downwardly and. outwardly from the upper endv of themember 24, to form an annular weather shield for the upper perforatedportion of the.- member' 24.

As shown in Fig. 1, the metal block. 2!} is secured, for example byscrewthreads and brazing, to the. upper end of av vertical mixing: tubeor chamber 21, which ispreferably substantially coaxial with the axisof' the chimney IS. The lower end of the mixing tube 21 is preferablythreaded to engage a mantle support 28 containing" a burner screen, notshown, which support in turn car:- ries a mantle 29 coaxially with themixing tube 2.1, so that fuel mixture delivered to the tube 2 1: isprojected centrally thereof and downwardly into the central portion ofthe mantle 29.

As shown in Fig. 2, the base plate i3 is provided with perforations 13bto supply external air to. the mantle 29 to assist in completely burningthe fuel mixture, said baseplate also being provided with an opening ltcto. facilitate inserting a lighted match or taper to. light the fuelatthe mantle 29 at the beginning. of the starting operation.

As shown in Fig. 3, the reservoir III is provided with aninclinedflattened portion Na in its side wall. just. below the top of thereservoir, to support. a threaded and outwardly extending sleeve 30having a borewhich is a Sliding fit on the outer surface of the-barrelof an. air pump 3!, which pump barrel is provided at itsouter end withan outwardly extending flange engaged by a flanged collar 32 havinginternal threads for engaging the threads on the sleeve 30. The endflange of the. pump barrel is. of substantially the same outer diameteras the threaded portion of the sleeve 30 and is correspondingly threadedto permit the collar 32 to pass over it to the position indicated inFig. 3, the inner threads in the collar 32 being cut away, so that whenthe collar is in the position illustrated in- Fig. 3, it may tum freelyrelatively to the pump barrel, in securing the pump in the reservoir. Asuitable packing ring is preferably employed between the barrel flangeand the end of the sleeve 30, to make a tight joint at that place. The:collar 32 is provided with a central bore which is a sliding fit on thepump plunger rod 31a, as a result of which the collar 32 constitutes theouter end wall of the pump barrel and also. a closing cap for the sleeve30, the bore of which sleeve constitutes the filler opening, for thereservoir Hi. As shown in Fig. l, the reservoir l 0. is preferablyprovided withan air-release valve lb of any known form, fordissipatingthe air pressure in the reservoir whenuse of the lantern isdiscontinued.

Asalso shown in Fig. 3-, the lower edge; portion of hood portion 24b isprovided with opposite perforations to receive the lower bent ends iii)of a bail 33, which bent ends are of a. conformation cooperating withthe hood portion 24b to prevent.- disengagement of the bail from thehood portion when the ball is in its lantern carrying position.

As illustrated in Fig. 3, the housing. oi the valve mechanism Itisprovidedwith an upwardly extending tubular branch Ha projectingthrough a suitable. clearance opening therefor in the. base plate l3,the upper and externally threaded end of said extension Ha engaging acollar 34 by which the generator tube 35 is supported and connected withsaid extension Ha, to hold the nozzle 22 in place in the block at. Thevalve mechanism is provided. with. a valve rod 36 by turning which, thestarting condition of the lantern. is effected for a desired interval.and by further turning which the running condition. of the lantern iseffected, as described below.

As shown in Fig. 4, the housing of the valve mechanism H is providedwith a downwardly extending portion projecting. into the reservoir EU,and held in place by external screwthreads engaging. similar internalthreads in. acollar 31 rigidly secured, for example by brazing, to thereservoir with the head of said collar in a recess therefor in thereservoir. Inside of the reservoir ID, the valve housing supports invertical position two tubes 38 and 39, the. tube 38 being. employed tosupply atomized fuel. and air from the reservoir, to the valve mechanismduring the starting condition of the lantern, while. the tube 39 servesto supply liquid fuel only to. the valve mechanism during the runningcondition of the lantern. The tubes. 38- and 39 are rigidly secured tothe housing of. the. valve mechanism by entering at their upper endssuitable bores in the housing of the valve mechanism, in which that theliquid freely entering the lower open end of the tube 38 from adjacentthe. bottom wall oi the reservoir Ill, may thoroughly wet the fillingThe tube 38.

material even when the fuel in the reservoir is nearly exhausted. Cottonfiber, wool fiber, or any fibrous material having a high degree ofcapillary action may be employed to fill the tube 38, the only requisitebeing that the filling material be not so tightly packed in the tube 38as to prevent the flow of air through the filling material under the airpressure developed in the reservoir 58 by the hand pump 3!. The tube 38is provided at its upper end with a screen 3811 and said tube issurrounded by a second tube 4! having a bore somewhat larger than theexternal diameter of the tube 33, to form an air space between the tubeti and the tube 38. The ends of the tube 4! are pressed inwardly toengage the tube 38 in a manner to maintain the air space between the twotubes, and the tube 4! is held in place preferably by brazing its endsto the tube 38. 'The outer tube 4! is provided with an air inlet opening42 above the highest level 43 of the liquid fuel in the reservoir E8,and the tube 38 is provided with an aperture 44 for air flow, which isjust above the lower end of the tube 4|, and in open communication withthe air space between the tubes 33 and 4|, and also with the interior ofthe tube 38.

As shown in Fig. 4 the housing of the valve mechanism l I is providedwith a horizontal bore 45 containing a first valve member 46 having anexternal diameter somewhat smaller than the bore 45 to permit the flowof fuel mixture between the valve member 46 and the bore 45 to adischarge passage 4'! in the extension I la, when the lantern is inoperation for the starting condition of the lantern, and tocorrespondingly permit the flow of liquid fuel to and through thepassage 41 when the lantern is in its running condition. The valvemember 46 is tapered at its inner end to engage a first valve seat 48 inthe housing of the valve mechanism, to control fuel mixture flow from apassage 49 in said housing which cmmunicates with the upper end or theinterior of the tube 38, and the other end of said valve member 48 isexternally threaded to engage corresponding threads in the housing bore45, s that turning the valve member 46 will move it towards or from itsseat 48 as desired. The valve member 46 carries a second valve member 50having a tapered end engaging a second valve seat in the housing of thevalve mechanism, so that said second valve member 59 will control theflow of liquid fuel from a passage 52 in open communication with theupper end of the tube 39, through a clearance space around the secondvalve member 58 for delivery to the passage 41 for the running conditionof the lantern. The valve member 50 is a sliding fit in the valve member46, and carries at its inner end an outwardly extending flange 53 whichis a sliding fit in the bore 46a in the valve member 46, in which borethe flanged end of the valve member 50 engages an antifriction ball 54which in turn is engaged by one end of a spring 55 contained in saidbore. The end of the bore 45a contains a sleeve 56 which fits said boreand has a sliding fit on the valve member 58. The sleeve 55 isexternally grooved at 56a to receive the compressed end of the valvemember 46, to hold said sleeve in place. The spring 55 is held incompressed condition by the inner end of the here 4611, the tension onthe spring being sufiicient to positively hold the valve member 58against its seat 5|, when the valve member 46 is moved a small distancefrom its seat 48, but not enough to engage the flange 53 with the sleeve56. The housing of the valve mechanism around the valve rod 36 is closedby a threaded collar 51 and packing ring 58 in the usual manner.

As a result of the valve mechanism construction described, after liquidfuel is placed in the reservoir I0 to any operative depth below thehighest permissible'level 43, and when the requisite air pressure hasbeen developed in the reservoir above the liquid fuel by the action ofthe hand pump 31, the starting condition of the lantern is establishedby turning the valve rod 36 sufiiciently to move the valve member 46from its seat 48, the amount required to permit atomized fuel and air toflow freely to the passage 41 and thus to the generator tube 35. Forthis condition of the valve mechanism, air under pressure flows throughthe aperture 42 downwardly and around the tube 38 between the tube 38and the tube 4|, into the tube 38 through the lower aperture 44, andthen upwardly through the fibrous material in the tube 38 which is thenwet with the liquid fuel. This subdivides the air flowing upwardly inthe tube 38 and in its passage upwardly through the fibrous material,the air picks up minute particles of the liquid fuel in a manner toatomize the liquid fuel and carry it in mixed condition with the airthrough the passage 49-and around the valve member 46 to the deliverypassage 4! where it is delivered to the generator tube 35. In a mannerto be described, the fuel mixture is delivered in burnable condition tothe mantle 25!,v

where it is ignited and in a very brief interval sufiiciently heats thegenerator due to the proximity to the mantle 29, to make it feasible tosupply liquid fuel to the generator instead of the atomized fuel and airmixture. To effect this change in operating condition, the valve rod 36is further turned to move it outwardly, thereby moving the valve member46 farther from its seat 48, the flange 53 is engaged by the sleeve 56,and continued movement of the valve rod 36 moves the valve member 58from its seat, thereby permitting the flow of liquid fuel withoutobstruction or hindrance of any kind through the tube 39, through thepassageway 52, around the valve member 50, around the valve member 46and to the delivery passage 4'! and thus to the generator 35, For thiscondition of the valve mechanism, although the path of travel from theinterior of the reservoir through the tube 38 and through the passage 49to the delivery passage 41, is still open and in the same condition asit was during the starting of the lantern, air is no longer taken fromthe reservoir, because the drop in pressure through the open fuel tube39 is substantially zero, and as a result, substantially the samepressure is exerted upon the upper end of the passage 49 as is exertedupon the aperture 42, which quite as effectively stops the further flowof air from the reservoir, as would be the case if valve mechanism wereemployed to positively shut the passage 49. In this manner by acomparatively simple valve mechanism, the air under pressure in thereservoir is utilized during the starting condition of the lantern tosupply the air required to make the fuel mixture for starting thelantern and heating the generator, and the same valve mechanism by meansof a single rotary valve rod, provides for establishing the runningcondition of the lantern by which liquid fuel is supplied as such to thegenerator tube by the air pressure in the reservoir l8, without howeverpermitting any appreciable flow of air from the reservoirto and throughthe valve mechanism. It is important that the length of air travelthrough :the fibrous material 40,. determined by the vertical locationof the aperture 44, the inner diameter of the tube 38, and the kind. ormaterial and degree; of packing of the material 40, shall be so chosenas to produce such. a degree of fuel atomization that the starting flamein the mantle will be neither too rich nor too lean; for if theatomization is too great, a rich mixture and smoky flame result, whichare not adapted to starting requirements,v and if the atomization is.too small, a lean mixture results which his difiicult or impossibletolight.

The fuel atomizing or carbureting devices illustrated in Fig. 4 as astartingmeans for a pres-- sure lantern, are: equally applicable as ameans for supplying an atomized or carbureted mixture from liquid fuel,toany desired liquid fuel burning devices, for example, stoves, torchesand similar devices.

As shown in Fig. 5, the generator tube 35 preferably but not necessarilyconsists of a lower por-- tion 350,. and an upper portion 35b ofrelatively small diameter, the lower end of the portion 35b entering theupper end of the lower portion 35a and being tightly secured to thelower portion after pressing the upper end of the lower portion around"it, for example by brazing the: parts together. The lower portion 350 ispacked or filled with material to prevent surging of the fuel mixturedelivered to the mantle, said packing or filling material beingpreferably of a nature involving long filaments of minute diameter, thefilaments preferably extending the entire length of the filling materialand being of a nature that will not readily break and produce smallseparate pieces of the material. The said filling materia1 mayadvantageously consist of glass filaments ofminute diameter and a largenumber of said filaments being used either in twisted condition to-'form a. yarn or not as preferred, a suilicient quantity of. saidfilaments being employed. to suitably fill the portion 35a. The fillerdescribed has the advantage that each of its filamerits may becontinuous from end to end of the filler material, and that it issufiiciently flexible and pliable so that it does not readily break andproduce small pieces of the material that might find their way throughthe: generator tube to the nozzle supported thereby and clog the outletopening of the nozzle. A further advantage of this filling material isthat the surface of the filaments is. smooth and presents a minimumopportunity for the deposit of carbon particles formed by thevaporization and distillation of the fuel, to engage and lodge on thefilling material. At the same time, the filling material serves as aneiiective filtering agent as to relatively large particles of foreignmatter that may be carried by the liquid fuel, to prevent their findingtheir way to the nozzle, without interfermg with the passage through thegenerator tube of minute and infinitesimal particles of carbon developedin the vaporization of the fuel, which as. a result of having no placeto lodge or accumulate, find" their way in separated condition to and.through the nozzle without clogging the latter. The portion 35b of thegenerator is unobstructed in any way and provides for free flow of the.fuel through it during the operation of the lantern. At the beginning ofthis flow and during the starting condition of the lantern, the liquidfuel flowing through the portion 35b is finely atomized and mixed withairso that when delivered from the nozzle to themantle, the mixture isin burnabl'e condition, and immediately iii aavassc that-the. burning ofthe fuel is begun in the mantie, on accountof the proximity of thegenerator to the mantle, the generator is rapidly heated so that-in aremarkably short; interval the generator is hot enough to begin thevaporization of the atomized particles of fuel, which continues untilthe heat of the generator is sufllcient to vaporize the liquid fuel ifsupplied to it in liquid condition and without atomization, as is doneduring the running condition of the lantern.

The upper end of the generator portion 35b is curved from verticalposition to horizontal position where it engages and is rigidly secured,for example by brazing, to the upper end of the i nozzle 22, said nozzlehaving a cylindrical outer position by a guiding and supporting tube 59carried by the block 20. The bore 22a is closed at its upper end and atits lower end is internally threaded to engage the correspondinglythreaded nozzle tip 222) provided at its lower end with a minutedischarge aperture 22c communicating with the bore 22d, the dischargeaperture 22c being coaxial with the nozzle 22. The nozzle 22 ,fits and.is freely movable vertically in the supporting tube 59,, to facilitateassembly of the generator 35 and to facilitate replacement of thegenerator when and if such a course becomes desirable.

As shown in Figs. 5 and 6,. the block 20 is provided with a centralaxial bore 26a of substantially larger diameter than the externaldiameter of the tube 59, which latter tube is coaxial with said bore.The bore 20a is closed at its upper end, and the tube 59 is supported insaid bore by threaded engagement with the top wall of the block'Zll,which connection may be further secured if desired, for example bybrazing. The air tubes l6 and I! open into opposite sides of the bore20a above the lower end of the tube 59, as a result of which the rapidflow of fuel mist or vapor as the case may be, from the nozzle tip 22bdownwardly and coaxiall'y with the bore 20a, produces an aspiratingeffect on air delivered into the bore 20a by the air tubes [6 and ll,which aspirating or Bunsen effect is accurately determined and adjustedby the location of the lower end of the tube 58 relatively tothedischarge ends of the air tubes l6 and IT. It frequently occurs inmanufacturing devices such as the generators 35, that it is diflicult toaccurately make them in all respects, duplicates of each other, and themanner of mounting the nozzle 22 in the tube 59 as just described,permits inaccuracies within reasonable tolerances, of the location ofthe. nozzle 22 relatively to the lower end. of. the generator 35 becausethe nozzle tip 222; may have one position or another vertically in thetube 59, as long as the tip 22b does not project below the tube 59, forany of which positions the efficient and optimum aspirating effect ofthe fuel vapor discharge on the inflowing air from the tubes I6 and I1,is maintained.

The lower end of the bore 20a is internally threaded to engagecorresponding external threads on the upper end of the mixing tube 21,and in this manner the mixing tube 2'! and the mantle 28 are supportedcoaxially with the bore 20a with the result that the stream of atomizedor vaporized fuel as the case may be, delivered from the aperture 22c,is centrally maintained in the mixing tube 21 and discharged centrallyinto the mantle 25, with little or no engagement between said fuelstream and the inner wall of the mixing tube 21, the mixing tube beingrelatively short to facilitate this result, which is also facilitated byconstructing the aperture 220 in the nozzle tip, so that the atomized orvaporized fuel stream delivered from the said aperture, will have but asmall amount of spread or divergence, as it passes downwardly throughthe mixing tube 21.

While the generator of the invention is not restricted to any particularsizes or measurements, one practical construction has been foundeffective in which the portion 35a of the generator is a brass tubehaving an external diameter of about a and a wall thickness of about ,6and in which the portion 35b is a brass tube having an inner diameter ofabout 1 and a wall thickness of about the discharge aperture 220 forthis construction being only a few thousandths of an inch in diameter,for example from sixto eight-thousandths of an inch. It is desirablethat the two portions of the generator shall be made of highly heatconductive material such as brass, and with the construction described,the moment heat is produced at the mantle 29 by the initial burning ofthe fuel, the generator is very rapidly heated so that in a few secondsvaporization of the fuel in the generator begins, and that in, forexample, forty seconds from the beginning of the burning operation withkerosene as the fuel, the generator is sufiiciently heated to properlyvaporize the liquid fuel for the running condition of the lantern, thestarting interval being much less where gasoline is used as fuel. It hasbeen found that with the generator constructed as described, there is noneed for the use of any devices to clean the nozzle aperture 220,notwithstanding its minute size, a possible explanation for this beingthe small diameter of the generator portion 35b and the correspondinghigh velocity of flow of the vaporized fuel through said tube, whichvelocity is maintained through the bore 22a and through the nozzle tip2%, thereby affording little if any opportunity for minute impurities orcarbon particles to lodge r in the burner tip and clog the same. Alantern constructed as described, has been operated con- -tinuously withgasoline for over 1800 hours without clogging the generator tube ornozzle aperture.

Another feature that is important, is that the upper portion of thegenerator, where the destructive distillation of the fuel occurs, andfrom there to the nozzle, should be very highly heated, which is foundto preventthe building up of objectionable carbon masses in thegenerator. The small exposed surface of the generator tubes, keeps theupper portion of the generator very hot, which materially contributes tothe effective enerator action described.

It will further be observed that the atomized or vaporized fuel streamdelivered from the nozzle 22b is projected through the mixing tube 2!coaxially therewith and without change of direction of any kind, so thatthe entire kinetic energy of the fuel stream is available to project theatomized or vaporized fuel into the mantle 29, thus avoiding appreciableengagement of the atomized or vaporized fuel with any metallic surfacesof the structure, and thereby avoiding appreciable collection of theatomized fuel particles and condensation of the vaporized fuel on saidsurfaces with resulting dripping of the collected fuel from saidsurfaces. In other words, the lantern in operation is substantially freefrom apfulness, than larger diameter generators.

preciable undesirable fuel collection, condensation and dripping.

The generator, nozzle and mixing devices illustrated in Figs. 5 and 6,may be used with advantage, wholly or in part, with liquid fuel burningdevices generally, whether for lighting purposes or not, andparticularly where it is desirable to avoid clogging and surging, andwhere the use of extraneous preheating devices is undesirable.

In connection with the operation of the lantern described, severalimportant considerations are involved as follows.

In a pressure lantern using kerosene as the fuel it is necessary topreheat the generator to a higher temperature than that required for amore volatile fuel such as gasoline. It is therefore desirable whenkerosene is used, to reduce to a minimum the weight of metal in thegenerator that must be heated, in order to reduce as much as possiblethe length of time required for preheating the generator.

We have found it very advantageous to employ a generator including. twodifferent sizes and weights of tubing, with the larger size at the lowerend suitable in size for housing a packing material adapted to preventsurging duringthe lantern operation, and with the smaller size at theupper end.

The small upper portion of the generator has a greatly reduced internalvolume per unit of length and the resulting rate of movement ofvaporized fuel therethrough is correspondingly increased. We have foundin practical tests that when the generator includes an upper sectionmade from a very small tube, this small section may be preheated in ashort time and that the deposit of carbon, produced by the destructivedistillation of the fuel during vaporization, is greatly reduced andthat a generator of this design will have greatly increased hours ofuse- Vaporizing liquid fuel by generators of the kind underconsideration, is always accompanied to some degree by the destructivedistillation of the fuel and the corresponding formation of free carbonparticles. These particles at the instant of forming, are extremelyminute, but in the presence of any favorable condition or structurethereto, they rapidly conglomerate to form appreciable and sizablemasses, which rapidly clog any filters or screens employed, as well asthe discharge apertures of the nozzles used. By our invention, insteadof attempting to cope with these conglomerate carbon masses after theyare formed, we prevent appreciable conglomeration of the minute carbonparticles, by highly heating the generator of small cross-section, andwe believe, what is equally important, we produce in the mannerdescribed, in the portion of the generator where most if not all of thedestructive d stillation of the fuel occurs, such an extremely h hvelocity of flow of the gases of volatilization, that the instant theminute carbon particles are formed, they are picked up and carried bythe gas stream as such, to'and through the nozzle and its dischargeaperture, with no opportunity to conglomerate into larger masses. Immediately upon being zle, the minute carbon particles ar i n mixed withair in the mixing tube and mi i ia: dehvered to the mantle in an idealcondition for effective and uniform comb ti When kerosene is used as thefuel in this class discharged from the nozof pressur lanterns, th dishar o fi e of th generator nozzle must be correctly positioned relativeto the air supply tubes and to the manifold or mixing tube, to ensuresufficient free air intake for the proper combustion of the kerosene,fuel containing a relatively large number .of heat units, it beingnecessary to produce a combustible mixture having a correct flame propaation and consequent flame size, to establish uniform heating andincandescence of the mantle. When gasoline is used in the lanternwithout any changein the generator nozzle, the air supply tubes and themanifold or mixing tube, and their relationship to each other, the flamepropagation of the gasoline mixture will be more rapid, because of thelesser heat units in such fuel and consequently the flame will be moreoxidizing in character and shorter in length and will not properly heatthe same mantle To cure the difiiculty just referred to, and to make thesame lantern equally effective with both kinds of fuel, we have foundthat a shutter may be employed to close the intake end of one of the airsupply tubes, and that when this tube is closed the air intake into themixing tube will be reduced to a degree to lessen the flame propagationand re-establish a flame of the necessary character and size for theproper incandescence of the mantle with the lighter fuel, withoutimpairing the effectiveness and efficiency of the lantern for operationwith the heavier fuel when the shutter is opened.

To maintain correct fuel and air mixing action, we have provided a,sleeve with an open lower end adjacent the delivery ends of the airsupply tubes and the manifold or mixing tube, and we have positioned thedischarge orifice of the generator nozzle within this sleeve. We findthat when the open lower end of this sleeve is fixed in a predeterminedoptimum location, the position of the discharge orifice of the nozzlemay be varied within the limits of the sleeve without appreciablyaffecting the said mixing action, which sleeve therefore permits the useof generators of slightly different lengths without modifying the mixingaction, as long as the discharge orifice is within the stationarysleeve. This conveniently accommodates small differences in length ofthe generators, usually incident to manufacturing operations, itobviates the need for accuracy in assembling the generators in thelanterns, and it makes the assembling and replacement of the generatorsa simple operation readily and successfully effected by unskilledpersons.

An important part of the invention consists of means for using arelatively non-volatile liquid fuel such as kerosene (coal-oil), fromwhich a suitable preheating flame isv produced for heating the generatorof a, lantern of the class described. The problem to be solved requiredmeans for producing a mixture of atomized kerosene and air of a desiredrichness, and the delivery of this mixture to a burner without change asto the atomized or finely divided condition of the fuel component.

Many successful devices are known for producing a carbureted mixture ofliquid fuel and air for use in preheating a lantern generator, when theliquid fuel used is relatively volatile, such as gasoline.

Generally in this latter class of preheating devices the air from thetop of the lantern reservoir is mixed in the reservoir with a very smallamount of gasoline to produce a carbureted mixture from the readilyvolatile gasoline, which mixture is a substantially stable, combustiblegas mixture that, when discharged from a nozzle, may be conductedthrough cold manifold tubes and if desired changed in direction by .suchtubes, without the fuel vapor condensing on the cold manifold tubewalls, the success of this class of preheating devices being dependentalmost entirely upon the high volatility of the fuel.

In the presentinvention means for producing an air and fuel mixture areprovided that consist of devices for conducting air from the top of alantern reservoir (above fuel level) into a wick laden with kerosene byits capillarity, and allowing this air to pass through a. predeterminedlength of this wick to atomize a. part of the kerosene and produce acombustible mixture, which, when discharged from a nozzle orifice, isdirected to a burner screen with little or no contact with the walls ofthe manifold tube being permitted, to thereby deliver to the burner .acombustible mixture for a preheating flame.

A critical part of the invention consists in a wick having a desireddensity and capillarity and in the length of the passage of the airthrough the kerosene laden wick. When this distance is too long, thecombustible mixture produced will be too rich in fuel and the preheatingflame therefrom will be very smoky and not suitable for generatorpreheating purposes; on the other hand, if the length of the air passagethrough the wick is too short, the combustible mixture will be too leanand it will be very difiicult if not impossible to ignite it at theburner.

In an illustrative practical embodiment of the starting carburetingdevices referred to, we used for the tube 38, a brass tube having anoutside diameter of of an inch and an inside diameter of of an inch, andof a length to reach nearly to the bottom of the reservoir t0, thefilling material 4i] consisting of 20 strands of 8/8 ply cotton yarninserted in and extending substantially from end to end of the tube; theinner diameter of the tube 41, which is not critical, was selected of asize to provide for free, air flow between the tubes 38 and 41, forexample, a radial space of about & to 5 of an inch; the air inletopening 42 was positioned vertically of the tube M to be well above thehighest level 43 of the liquid fuel in the reservoir ID. the position ofthis opening being not otherwise critical; and the aperture 4 1 waspositioned vertically of the tube 38, to provide a vertical length oftravel of substantially 1% inches through the filling material 40 ladenwith relatively nonvolatile liquid fuel such as kerosene, for airentering the said filling material through said aperture 44, this lengthof travel for optimum results being rather critical for the illustrativeconstruction described. With the construction just described, the airand atomized fuel mixture lighted readily, there was but little smokeproduced even at the instant of lighting, and the generator was heatedvery rapidly to establish the running condition of the lantern. Wefurther found that the richness of the air and fuel mixture wassubstantially constant, independent of the height of the fuel level inthe reservoir.

While we have described our invention as applied to a lantern, it willbe understood that the novel described features of the invention may beadvantageously used with other forms of pressure lighting devices of themantle type, such as mantle lamps of various kinds, and that some or allof said features of the invention may be effectively used in liquid fuelburning devices of the pressure type that are not primarily intended forlighting purposes, such as stoves, torches and heating devicesgenerally.

While the invention is disclosed in the particular embodiment abovedescribed, it is understood that it is not limited thereto, asequivalents thereof may be employed without departing from the scope ofthe appended claims.

Having thus described our invention, what we claim is:

1. In a liquid fuel burning device of the pressure type for starting andrunning on heavy liquid fuel such as kerosene, and including a mixingtube, a generator tube for supplying fuel to said mixing tube, areservoir for liquid fuel, and valve mechanism for supplying atomizedfuel to said generator tube for starting'purposes and for supplyingliquid fuel to said generator tube for the running condition of thedevice, devices for atomizing said heavy fuel including in combination astarting tube extending downwardly in said reservoir from said valvemechanism to adjacent the bottom of the reservoir and open at its lowerend into the reservoir, fibrous capillary filling material in saidstarting tube and wetted at its lower portion by said heavy liquid fuel,and

an air conduit from above the upper fuel level in said reservoir to theinterior of said starting tube below said upper fuel level, the wall ofsaid starting tube being imperforate above the air delivery end of saidconduit.

2. In a liquid fuel burning device of the pressure type for starting andrunning on heavy liquid fuel such as kerosene, and including a mixingtube, a generator tube for supplying fuel to said mixing tube, areservoir for liquid fuel, and valve mechanism for supplying atomizedfuel to said generator tube for starting purposes and for supplyingliquid fuel to said generator tube for the running condition of thedevice, devices for atomizing said heavy fuel including in combination astarting tube extending downwardly in said reservoir from said valvemechanism to adjacent the bottom of the reservoir and open at its lowerend into the reservoir, fibrous capillary filling material in saidstarting tube and wetted at its lower portion by said heavy liquid fuel,a second tube around and spaced from said starting tube and sealed atits ends against said starting tube and extending from above the upperfuel level in said reservoir to substantially below said upper fuellevel, said second tube having an air opening therethrough above saidupper fuel level, and said starting tube having an air openingtherethrough below said upper fuel level and above the lower end of saidsecond tube, the wall of said starting tube being imperforate above saidair opening therethrough.

3. As a means for producing a fuel mixture of air and atomized fuel forstarting purposes from heavy liquid fuel such as kerosene in a liquidfuel burning device of the pressure type including a fuel reservoir anda generator tube, the combination of a starting tube for startingcommunication with said generator tube and extending from above theupper fuel level in said reservoir to adjacent the bottom of saidreservoir, fibrous capillary filling material in said starting tube andwetted at its lower portion by said heavy liquid fuel, and an airconduit from above the upper fuel level in said reservoir to theinterior of said starting tube below said upper fuel level, the wall ofsaid starting tube being imperforate above the air delivery end of saidconduit.

4. As a means for producing a fuel mixture of air and atomized fuel forstarting purposes from heavy liquid fuel such as kerosene in a liquidfuel burning device of the pressure type including a fuel reservoir anda generator tube, the combination of a starting tube for startingcommunication with said generator tube and extending from above theupper fuel level in said reservoir to adjacent the bottom of saidreservoir, fibrous capillary filling material in said starting tube andwetted at its lower portion by said heavy liquid fuel, a second tubearound and spaced from said starting tube and sealed at its ends againstsaid starting tube and extending from above the upper fuel level in saidreservoirto substantially below said upper fuel level, said second tubehaving an air opening therethrough above said upper fuel level, and saidstarting tube having an air opening therethrough below said upper fuellevel and above the lower end of said second' tube, the wall of saidstarting tube being imperforate above said air opening therethrough.

5. In a pressure type liquid fuel burning device adapted for burningheavy liquid fuel such as kerosene, the combination of a generator, areservoir for the liquid fuel, valve means connected with said reservoirfor controlling the flow of the starting mixture to said generator, astarting tube extending in said reservoir from said valve means,capillary fibrous material in said tube, said fibrous material beingdisposed for wetting by said liquid fuel, and means for supplying air tothe interior of said tube below the fuel level in said reservoir and ata distance from the valve-connected end of said tube effective toatomize heavy liquid fuel such as kerosene by the flow of said airthrough said fibrous material, said tube being imperforate between saidair supply thereto and said valve means, whereby for start-- ingpurposes a combustible mixture of atomized heavy liquid fuel such askerosene and air is delivered from said starting tube through said valvemeans to said generator.

6. A pressure lighting device of the inverted mantle type for operationwith heavy liquid fuel non-volatile at room temperature such askerosene, including in combination a downwardly directed fuel nozzlehaving a discharge aperture at its lower end, means for supplyingatomized heavy liquid starting fuel such as kerosene under pressure tosaid nozzle, a mixing tube below said nozzle and substantially coaxialwith said discharge aperture, and a mantle support at the lower end ofsaid mixing tube and substantially coaxial therewith, said dischargeaperture having a conformation projecting a stream of said atomizedstarting fuel through said mixing tube of smaller diameter than theinternal diameter of said mixing tube, thereby avoiding undesirablecollection and liquefaction of said atomized starting fuel on the innersurface of said mixing tube during the starting operation of thepressure lighting device when said mixing tube is in unheated condition,and in turn avoiding the dripping of said atomized fuel from saidstarting tube onto and through the mantle of the lighting device duringsaid starting operation.

ROBERT BAKER. CORTLAND W. DAVIS.

